Cyril of Alexandria

But Christ was the mystery which has been revealed in the last times of the world, having been prepared before the foundation of the world. Hence it follows, which thou hast prepared before the face of all men.

Catena Aurea by Aquinas ↗

Theophylact of Ohrid

"He prepared... this salvation before the face of all people." For He became incarnate in order to save the world and so that His incarnation would be made manifest to all.

Commentary on Luke ↗

Ancient Greek Expositor

Mark the wisdom of the good and venerable old man, who before that he was thought worthy of the blessed vision, was waiting for the consolation of Israel, but when he obtained that which he was looking for, exclaims that he saw the salvation of all people. So enlightened was he by the unspeakable radiance of the Child, that he perceived at a glance things that were to happen a long time after.

Catena Aurea by Aquinas ↗

Bonaventure

But this salvation was not particular, but universal; and therefore he adds: Which you have prepared before the face of all peoples, according to that word of Isaiah 52: "All the ends of the earth shall see the salvation of our God." He already saw verified that word of the Psalm: "The Lord has made known his salvation; in the sight of the nations"; there follows: "All the ends of the earth have seen the salvation of our God"; Isaiah 49: "It is a small thing that you should be my servant for converting the remnants of Israel. …

Commentary on Luke, Chapter 2 ↗